Comment thread started by Jay Rogers on Virtual Machine Compute Optimizer

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Jul 23, 2019

In testing this in my lab and reading the vCPU rightsizing blog in your document, I don't understand how to set what you output shows for many VMs.
In vCenter Web Client we can adjust CPU & Cores per Socket. Most best practice docs have said keep Cores per socket to 1 except when exceeding NUMa or for workloads like SQL. In my example VM I had 4 CPU (top line) and 1 Cores per socket defined for Server 2019 VM. The script said to change this to 1 CPU (top line) and 4 cores per socket (optimal sockets=1, optimal cores=4). You cannot adjust bottom cores per socket past 1 unless CPU (top line is greater than 1 CPU. Am I missing something here?

Jul 23, 2019

Within the VM config (Edit the VM), you set a total number of CPUs to be assigned to that VM and then set "Cores per Socket" - the Sockets is calculated for you and displayed in the UI right next to the Cores per Socket drop down.

So yes, you need to set the VM to have 4 CPUs with the first dropdown, then set the Cores per Socket drop down to 4 and you will see 'Sockets' next to that drop down change to 1. That's the optimal config: 1 vSocket x 4 Cores per Socket.

For a full history on Cores per Socket see: https://blogs.vmware.com/performance/2017/03/virtual-machine-vcpu-and-vnuma-rightsizing-rules-of-thumb.html

Jul 23, 2019

Wow, Thanks for the tool and articles. This is a lot different from the best practice we have used for so long as Mark mentioned in his blog.

Jul 24, 2019

Jay, I did a bug fix and uploaded a new version (1.0.3), so make sure to use that going forward!